Intermediate-moisture frozen foods

ABSTRACT

A microbiologically stable intermediate moisture sugared egg yolk composition containing egg yolks, dextrose plus fructose, about water, and about stabilizer. This product is soft and non-crystalline at freezer temperature.

CROSS-REFERENCE

This application contains subject matter divided out of U.S. Pat.application Ser. No. 917,379, filed June 20, 1978 now abandoned, U.S.Pat. application Ser. No. 871,995, filed Jan. 24, 1978 now U.S. Pat. No.4,154,863, and U.S. Pat. application Ser. No. 763,613, filed Jan. 28,1977 now U.S. Pat. No. 4,146,652, and is also a continuation-in-part ofsaid applications.

BACKGROUND OF THE INVENTION

A recent development in the food industry is the emphasis onintermediate-moisture foods which have the faculty of being stored andmarketed in a substantially non-refrigerated condition. These foods weredesigned to avoid the need to be packaged in a hermetically sealedcontainer and commercially sterilized or maintained in a frozen orrefrigerated state throughout the period of distribution and storage bythe consumer.

The intermediate-moisture foods are based on the principle of reducingthe availability of water in the food for microbial growth. Theavailability for spore germination and microbial growth is closelyrelated to its relative vapor pressure, commonly designated as wateractivity. It was found that the use of a wide variety of water-solublesolutes, or osmotic agents, has the effect of depressing the wateractivity of the foods to levels at which most bacteria will not grow.

The water activity of a food is defined as the partial pressure of waterin the food divided by the saturation pressure of water at thetemperature of the food. The water activity can be determined by placinga sample in a container which is then sealed, and after equilibrium isreached, determining the relative humidity above the sample. Mostproducts of this type have between 10 to 40% moisture, and a wateractivity between 0.65 and 0.9.

An early application of the technique of controllling water activity wasfor animal foods. For example, U.S. Pat. No. 3,202,514, issued Aug. 14,1965, discloses an animal food having 15 to 30% moisture and 15 to 35%water-soluble solids, principally sugar, with a proteinaceous meatysubstance. Subsequently, other foods were formulated with anintermediate-moisture content, such as egg products (U.S. Pat. No.3,640,731, issued Feb. 8, 1972), pancake batter (U.S. Pat. No.3,753,734, issued Aug. 21, 1973) and whippable bases for confectionaryuse (U.S. Pat. No. 3,958,033, issued May 18, 1976). The water contentand water activity of these foods are brought to as low a value aspractical to insure their long-term stability withou refrigeration. Themain difficulty with these foods is that their low-moisture content maydetract from their palatability, texture and mouth-feel. This techniquetherefore has found its greatest commercial applicability in thepet-food market where palatability requirements are not as stringent.

It is of course desirable to be able to avoid refrigeration and freezingof food products to reduce the cost involved, and particularly for theconsumer, to avoid the inconvenience of unpacking, handling, and thendefrosting the typically rock-hard frozen foods. However, freezing is anextremely safe and suitable technique for long-term storage and providesthe manufacturer with great leeway in incorporating any of a widevariety of ingredients in foods which would otherwise be short-lived.

Accordingly, a class of intermediate-moisture foods has been found inaccordance with application Ser. No. 763,613, filed Jan. 28, 1977, andapplication Ser. No. 871,995, filed Jan. 24, 1978, which combines theconvenience of the freezing method of storage sought by manufacturerswith the ease of handling desired by consumers. Such foods are normallystored at freezer temperatures, but upon removal from the freezer can beore readily handled because they retain a flexible consistency, arenon-crystalline and spoonable within about 5 to about 15 minutes, andcan be left at room temperature for an extended period of time as theypossess the requisite microbiological stability.

The foods of the invention are generally characterized by a high sugarcontent, usually at least equal in weight to the amount of waterpresent, in order to provide microbiological stability. The sugarsemployed have a low molecular weight, being primarily dextrose andfructrose, which comprise together at least about 50% and preferably atleast about 75% of the total sugar content. Sucrose has a sweetnessbetween that of fructose and dextrose. The fructose, which is sweeterthan the dextrose, is preferred since it has a lesser tendency tocrystallize and cause apparent hardness. For most foods, particularlywhere the food comprises an emulsion, it is preferred that the fatsused, if any, include partially unsaturated fats which tend to providesuperior flow properties and nutritional advantages, although lessstable than saturated fats. The fat content is usually less than thewater content in order to form a stable oil-in-water emulsion; the watercontent is preferably at least about 25% greater than the fat content.

The use of bacteriostatically effective amounts of sugar, however,imparts excessive sweetness to the ultimate food product. The problem ofexcessive sweetness has arisen previously in conjunction with thedevelopment of artificial sweeteners, and certain bitterness principleshave been incorporated in such products to mask the undesirable taste.It was disclosed in U.S. Pat. No. 3,934,047, issued Jan. 20, 1976, thataddition of aluminum potassium sulfate, naringen or a combinationthereof to artificial sweeteners such as the saccharines or thecyclamates, or to higher caloric sweeteners such as sucrose, effectivelyreduced the perceived sweetness and bitter after taste of the artificialsweetener. It was postulated that the bitterness agent reduces theduration of sweetness, and presumably alters the manner in whichsweetness is perceived.

In connection with neturalizing the bitter after taste of saccharine orsaccharine salts, it was disclosed in German Patent No. 2,060,634,issued Dec. 9, 1970, that the addition of about from 0.2 to 2.0 byweight percent of one or more substances having a bitter taste resultsin masking of the lingering bitterness associated with saccharine.Quinine sulfate and magnesium sulfate are specifically recommended asadditives for use in this regard.

Such bitterness principles as quinine, theobromine and caffeine havealso been advanced for use as flavor factors in synthetic and naturalchocolate compounds and chocolate-flavored beverages to impart a bittertaste to the resultant foodstuff. U.S. Pat. No. 2,835,592, issued May20, 1958, and U.S. Pat. No. 3,102,815, issued Sept. 3, 1963, areillustrative of such disclosures.

Further flavor modifiers which impart a bitterness to the compounds inwhich they are incorporated are disclosed in U.S. Pat. No. 3,647,482,issued Mar. 7, 1972, to Yueh, and U.S. Pat. No. 4,006,261, issued Feb.1, 1977, to Pickenhagen et al. Yueh's patent discloses the use ofribonucleotides, ribonucleosides and their deoxy analogues to reduce oreliminate the bitter after taste associated with saccharine orsaccharine salts, or compositions containing these sweeteners.Pickenhagen et al. disclose the use of compositions of theobromine incombination with cyclic dipeptides to impart bitterness and astringencyproperties to various foodstuffs, especially cocoa products, animalfoods, beverages, pharmaceutical preparations and tobacco products.

In U.S. Pat. No. 3,371,543, issued Feb. 13, 1973, the use oftheobromine, caffeine or naringen to impart bitterness to nitrogen-basedflavor intensifiers is disclosed.

It is an object of the present invention to provide a class of foodswhich are normally maintained at freezer temperature, but whic possessthe requisite microbiological stability for storage at refrigerator orroom temperature for an extended length of time without spoilage.

It is another object of the present invention to provide an improvedbacteriostatic intermediate moisture food product which is ready for useat freezer temperature, the perceived sweetness of which has beenreduced through the addition of a bitterness factor.

It is a further object of this invention to accomplish theabove-specified reduction in sweetness perception through the use ofcertain quinine salts.

Other objects, and advantages, of this invention will be apparent fromthe ensuing specification and examples.

THE INVENTION

The present invention is directed to microbiologically stableintermediate-moisture foods and other products which are normallymaintained at freezer temperature. The principles and techniques whichhave been developed for intermediate-moisture foods are applicable tothe present invention, as modified in the manner explained herein below.Many of the foods of this invention are maintainable at freezertemperature in a condition ready for immediate use. After removal fromthe freezer the foods may be held at room temperature or at refrigeratortemperature for a considerable period of time without spoilage becauseof the bacteriostatic effect of the sugar/water ratio.

The foods of this invention are generally characterized by a high sugarcontent, usually at least equal in weight to the amount of water presentin order to provide microbiological stability. The sugars used have alow molecular weight, being primarily dextrose and fructose, whichcomprise together at least about 50% and preferably at least about 75%of the total sugar content. Sucrose has a sweetness between that offructose and dextrose. The fructose, which is sweeter than the dextrose,is preferred since it has a lesser tendency to crystallize and causeapparent hardness. For most foods, particularly where the food comprisesan emulsion, it is preferred that the fats used, if any, includepartially unsaturated fats which tend to provide superior flowproperties and nutritional advantages although less stable thansaturated fats. The fat content is usually less than the water contentin order to form a stable oil-in-water emulsion; the water content ispreferably at least about 25% greater than the fat content.

The high levels of sugar requisite to effect bacteriostasis may renderthe ultimate food product excessively sweet, however, and thus lesspalatable to some consumers. In accordance with this invention, it hasbeen found that the addition of a bitterness principle modifies theundesirable sweetness of the sugar. More specifically, addition of aquinine salt, such as quinine sulfate, quinine bisulfate or quininehydrochloride, results in reduced perception of sweetness. In manycases, the perceived sweetness is reduced by more than half the valueassociated with the unmodified food product. Quinine salts are employedin this regard in amounts up to about 125 p.p.m. per food stuff. Apreferred range of such additive amounts is from 2 to 75 p.p.m.

An important group of foods which has been particularly well-adapted inaccordance with the present invention consists of the oil-in-wateremulsions, including butter creams, whipped toppings, low-fat whippedcreams, milk mates, non-dairy shakes, icings and coffee creamers.

Another class of goods, which forms a unique combination with theforegoing, is bakery products such as cakes, breads, cookies, pieshells, muffins, turnovers, pancakes, waffles and doughnuts. Thepastries can be filled or topped with the creams and icings of thisinvention.

Many diverse foods can likewise be adapted pursuant to this invention,such as dressings, puddings, sauces, gravies, snack spreads, pancakesyrups, ice creams, candies, and beverage (soup, tea, juice)concentrates, and meat, fish, fruit and vegetable products.

The foods of this invention are generally characterized by a wateractivity of about 0.75-0.90, up to about 0.93, a sugar to water ratio ofabout 1:1 and a sugar content which is at least 50% dextrose, fructose,or a combination thereof. In addition, many of the foods of thisinvention are adapted to remain spoonable or pourable at freezertemperature. Although most intermediate-moisture products willconventionally have a water activity below 0.85, some sacrifice intexture and taste may be required to meet this standard. Since the foodsof this invention are maintained at freezer temperature until ready tobe used, a water activity of 0.85-0.90, up to about 0.93, is adequate.Freezer temperatures of course are adequate to maintain themicrobiological stability of foods and even moderate control of wateractivity is adequate to extend the useful life of these products afterremoval from the freezer. Freezer temperature, unless otherwiseindicated, refers to temperatures of from about -5° F. to +10° F., whichrepresents a common range for both home and store freezers.

The standard of being spoonable refers to the texture or flexibility ofthe product, as well as to the quality of being able to eat the foodwhen it is at freezer temperature. The quality of being spoonable asused in this description is one which gives a satisfactory reading on astandard penetrometer and/or flow test, i.e., gave a penetrometerreading above about 3mm.

The products of this invention having a penetrometer reading of about 3mm or below are substantially non-crystalline, however, and becomespoonable within a very short period of time upon removal from freezertemperatures and introduction to room temperature (about 72° F.),generally within about 5 to about 15 minutes. Such non-crystalline-typeproducts can be used immediately in mixing, blending and various otherfood preparation procedures, although generally not considered quiteflexible or soft enough for immediate consumption.

Pourable products of this invention are more fluid and are tested byflow characteristics, generally about 30 ml per minute and higher duringthe first five minutes after removal from the freezers.

The products, of this invention present highly significant results whencompared to the standard, rock-hard frozen products currently on themarket. Details of the testing procedures are specified below.

The water activities of the foods of this invention are usually about0.75 t 0.90. Generally, the water activity is at the higher end of thisrange, i.e., about 0.85-0.90, up to about 0.93. Although microbiologicalstability is inversely proportional to water activity, several desirableproperties of food are adversely affected at very low water activity,e.g., mouth-feel and taste. Since the foods of this invention arenormally held at freezer temperatures for long-term stability, it ispractical to formulate foods which have water activities nearer theborderline of microbiological stability, which is about 0.90-0.93.

Several mathematical methods are available for calculating wateractivity, even of formulations containing different solutes and withnon-solutes. Rough calculations based on the additive effect of thenumber of moles of each component multiplied by the activity of thecomponent are useful for estimating water activity. Such calculationsreduce the number of experimental measurements that might otherwise beneeded and thus assist in reaching a suitable formulation more quickly.A combination of mathematical techniques with trial and errorexperiments followed by analytical measurements for determining wateractivity will lead to acceptable results.

There are commercially available devices for measuring the wateractivity of formulations. For example, a formulation may be placed in acontainer until equilibrium is reached and then the humidity in thecontainer measured. The water activity is then determined throughreference to standard tables. For example, electric hygrometers aredevices commonly used to measure water activity. These devices containsensors impregnated with salts such as lithium chloride or potassiumchloride. Water is adsorbed on the sensor and causes a change inelectrical resistance which is measured by a wheatstone bridge.Reference curves based on solutions of known humidity are used to relatethe electrical readings to water activity.

Throughout this application all amounts are by weight unless statedotherwise. In the examples the amounts have been adjusted to a basis of100. Percentages are based upon total formulation weight, unless adifferent basis is given.

Many of the foods of this invention are generally characterized asmicrobiologically stable food products comprising about from 15 to 45%water, sugar in a ratio to water of about 1:1 to 2:1, preferably aboutfrom 1.5-1:1, and minor but effective amounts of salt, emulsifier,stabilizer and flavoring, provided that the foregoing comprises at leastone of fructose and unsaturated fat, that the amount of fat, if any, isless than the amount of water or equivalent phase, such as non-aqueouswater-soluble liquid phase, the solutes content is adequate to providethe product with a water activity of about from 0.9-0.9, up to about0.93, the amount of dextrose plus fructose is at least about 50% basedupon the total sugar content, and wherein the foregoing ingredients areadapted to provide a product which is substantially non-crystalline atfreezer temperatures. Further, the foods of this invention may compriseup to about 125 p.p.m. of a quinine salt.

Certain other foods of the instant invention are characterized by theabove general formulation exclusive of the restriction specifying thatthe ingredients comprise minor but effective amounts of salt, emulsifierand stabilizer, and the ratio to water of sugar. Other foods maycomprise saturated fat, the total amount of fat comprising about from2.5 to 30%.

A preferred class of foods is microbiologically stable oil-in-wateremulsion cream-type products, such as butter creams, whipped creams,shakes, non-dairy creamers, etc., which comprise about from 25 to 45%water, sugar in a ratio to water of about from 1.5-1:1, about from 10 to30% fat, and minor but effective amounts of protein, salt, emulsifier,stabilizer and flavoring, a water activity of about from 0.8 to 0.9,wherein the amount of fructose is about from 15 to 65% based on thesugar content and the amount of dextrose is at least about 50% basedupon the remaining total sugar content, the fat content preferablycontains at least about 10% unsaturated fat and the foregoingingredients are adapted to provide a product which will flow at about10° F. Such preparations may also comprise preferably about from 3 to 20p.p.m. of a quinine salt. When the sugar component of the non-dairycreamer formulation is modified to contain only dextrose, amicrobiologically stable food product is produced which remainssemi-soft and substantially non-crystalline rather than spoonable atfreezer temperature.

These oil-in-water emulsion products have excellent texture and eatingproperties and are readily whipped to a high volume with a light butfirm structure. In addition to microbiological stability, these productshave physical stability in that they retain a smooth foamed cellularstructure without separation of a liquid portion. The products arefurther characterized by having an overrun of greater than about 150%and a density as low as about 0.3 or 0.4 for a butter cream and awhipped cream.

Another class of useful products is the flour-based foods. The battersfor these products comprise conventional amounts and types of flourdepending on the final product, about from 15 to 40% water, sugar in aratio to water of about from 1.5-1:1, about from 2 to 10% or up to 25%fat, and minor but effective amounts of leavening agent which may beencapsulated, egg products, salt, emulsifier, stabilizer and flavoring,provided that the solutes content is adequate to provide the productwith a water activity of about from 0.8 to 0.9, the fructose content ofthe sugar preferably is about 10 to 40%, the amount of dextrose plusfructose is at least about 50% or from 75 to 100% based upon the totalsugar content, and the fat is preferably unsaturated. The batter shouldhave at least one of fructose and unsaturated fat to assist in providinga spoonable and preferably a pourable product at about 10° F. The finalproduct made from the batter has a higher penetrometer value thatconventional products at 10° F. and is edible at that temperature. Suchpreparations may also comprise preferably about from 5 to 100 p.p.m. ofa quinine salt.

A unique combination is prepared from a bakery product and a cream-typeproduct, each made in accordance with this invention. Further, fruit(which may be infused with solutes) may be added to the bakery productsand the cream-type products. The water activity of the bakery productand cream-type product when used in combination should be approximatelythe same, plus or minus 0.05 units, or up to 0.10 units deviation fromeach other. When the water activity values are comparable there is lessof a tendency for water transfer as, for example, between a cake and itstopping or filling.

Microbiologically stable soup concentrates and sauces have been madecomprising about from 30 to 45% water, sugar in a ratio of water ofabout from 1.5-1:1, about from 5 to 30% fat, and minor but effectiveamounts of salt, stabilizer and flavoring, wherein the amount ofdextrose plus fructose is at least about 50% based upon the total sugarcontent, the foregoing ingredients comprise at least one of fructose andunsaturated fat and the product is spoonable at about 10° F. Fish, meatand vegetables (which may be infused with solutes) are added to these toprovide, for example, a chowder concentrate or newburg sauce. Suchpreparations may also comprise about from 5 to 100 p.p.m., preferablyabout from 30 to 70 p.p.m., of a quinine salt.

Microbiologically stable beverage concentates, for example, tea, orangejuice, etc., are made in accordance with this invention. They generallycomprise about from 35 to 45% water, sugar in a ratio to water of about1.8-2:1, and minor but effective amounts of flavoring, provided that theamount of fructose plus dextrose is about from 75 to 100% based on thetotal sugar content and the amountof fructose is about from 10 to 30%based upon the total sugar content, wherein the foregoing ingredientsare adapted to provide a product which will flow at about 10° F. Suchpreparations may also comprise preferably about from 5 to 50 p.p.m. of aquinine salt.

Microbiologically stable pudding products have been made comprisingabout from 25 to 45% water, sugar in a ratio to water of about from2-1:1, about from 3 to 25% fat, preferably unsaturated, and minor buteffective amounts of gelling agent, emulsifier, stabilizer andflavoring, provided that the amount of dextrose plus fructose is atleast about 75% of the total sugar content, wherein the foregoingingredients are adapted to provide a product which is spoonable at about10° F. Such preparations may also comprise about from 5 to 75 p.p.m.,preferably 10 to 20 p.p.m., of a quinine salt. Fruit, which may beinfused with solutes, may be added to the pudding products of thisinvention. Suitable pudding products include bread, rice, and plumpudding.

Microbiologically stable meat products, such as hotdogs, hamburgers,sausages and various meat loaves, are also made in accordance with thisinvention. Standard recipes for such products, known to those skilled inthe art, are modified through this invention to contain (1) enhancedamounts of sugar, preferably fructose, in place of conventional sugarnow used in amounts up to several times greater than those presentlyemployed or (2) an infused solution of sugar in a ratio to water of atleast 1:1, and, in either case, (3) fat in an amount less than theamount of water or equivalent phase, wherein the fat is substantiallyunsaturated, i.e., 50% or more, or preferably 75% or more of the fat isunsaturated. Furthermore, a quinine salt may be added in an amount notexceeding 125 p.p.m., and preferably falling within the range of 7 to 75p.p.m. These modifications are incorporated in the compositions of suchmeat products to provide increased microbiological stability and thusextend the shelf-life of such goods.

The apparatus for measuring the flow characteristics of the products ofthis invention was fabricated from stainless steel, and was essentiallya stand 14"×12", with a movable platform of the same size to provide forvertical and angular adjustments. The platform was provided with abulls-eye level and a protractor level; with the leading edge having awire brace to retain the sample container.

The following method was used in obtaining the flow data. Graduatedcylinders of 600 ml. capacity were filled with the samples and frozenfor at least 24 hours at +5° F. The frozen samples were removed from thefreezer, immediately placed on the platform in a horizontal (0°)position, and the effluent collected in other graduated cylinders, withthe volume noted at timed intervals. Temperatures were monitored with aHoneywell recorder. Sample temperatures within the freezer varied from+4° F. to +7° F. over a four-week interval, but varied no more than 1°F. over an 8 hour period, while the temperature in the freezer variedfrom +5° F. to +15° F., each time the door opened. Room temperaturevaried about 2° F. for an average of 72° F., while the temperature ofthe samples in the original container rose anywhere from 1° F. to 14° F.during the 15 minutes after removal from the freezer.

The penetrometer test and equipment used are standard. The penetrometeris made by Labline Instrument Co. Inc., Chicago, Illinois. The devicemeasures the penetration into the sample of the point of a hard rubbercone which weighs 12 grams and has a height of 11/2" and a diameter of11/2" at its base. The inverted cone is supported by a freely-slidingbar which weighs 48 grams. For all measurements the sample was broughtto a temperature of -7° F. in a freezer and then removed from thefreezer and immediately tested.

The products of this invention exhibited freeze-thaw stability instorage. The products were kept in a supermarket-type freezer unit whichcycled six times a day between application of cooling to freeze theproduct and application of heat to defrost the unit. Under theseconditions the products remained acceptable and functional.

The liquid emulsions were examined by dipping a spatula in the emulsion,letting it drain and noting whether the residual film was smooth anduniform or whether particles were present, a condition denotingdestabilization. These emulsions were also evaluated for their intendedfunctional application.

The products passed the following test procedures:

(a) The non-dairy creamer concentrates were tested in coffee forwhitening ability, signs of free oil on the surface or curdledappearance, and presence of oil globules or curdling indicating emulsionbreakdown.

(b) The semi-solid products which are consumed as such, e.g., puddingand cocktail sauce, were tested for syneresis and appearance (texture).

The method of making a microbiologically stable food product of thisinvention generally comprises mixing together about from 15 to 45%water, sugar in a ratio to water of about from 2-1:1, about from 2.5 to30% fat, and minor but effective amounts of salt, emulsifier, stabilizerand flavoring, provided that the amount of fat is less than the amountof water, the solutes content is adequate to provide the product with awater activity of about from 0.8 to 0.9, and the sugar comprises atleast about 50% dextrose plus fructose; pasteurizing the mixture andcooling the resultant product. Up to about 125 p.p.m. of a quinine saltmay also be employed in the mixing step.

A preferred method for preparing an emulsion product of this inventioncomprises blending all of the ingredients in the desired ratios. Usuallymost of the non-fat ingredients are first dispersed in the water. Theingredients are heated prior to or during blending. For example, theheating may begin during the mixing of the non-fat ingredients, and thenthe emulsifiers and fats added. The fat protein may also be preheatedand then admixed. The ingredients are pasteurized by holding at anelevated temperature for several minutes, i.e., at 180° F. for fiveminutes.

The blended ingredients are then passed through a homogenizer of thetypical dairy type. Although homogenization may be accomplished in onestage, it is carried out in two stages for best results. Preferably, thepressure during the first stage is maintained at a minimum of about2,000 psi and a maximum of about 10,000 psi, most preferably about 3,000psi, and the pressure during the second stage is maintained at about 500to 1,000 psi, preferably about 500 psi. The mix is usually maintained ata temperature of about from 60° to 75° C. during homogenization. Theemulsion is cooled to a temperature of about from 0° to 25° C. andpassed through a whipper for the incorporation of air or an inert gassuch as nitrogen, carbon dioxide, nitrous oxide or the like. The whippermay be of conventional construction such as a Hobart mixer or an Oakescontinuous mixer that permits cooling of the emulsion to temperatures ofabout 5° to 15° C., preferably 10° C., during whipping. The emulsion canbe whipped to an overrun of from about 100% to 500%, packaged andfrozen.

Sugar is employed as the principal source of water soluble solids andtypically may range in weight percentage of the composition anywherefrom 30% to 60% depending upon the particular sugar and sugar mixturerelied upon to offer the desired bacteriostatic protection. Loweramounts of sugar may be used if offset by increased levels of othersolutes. As the moisture content of the product increases in theintermediate-moisture range, the level of a given sugar will generallycorrespondingly increase in order to maintain a sufficientbacteriostatic effect. The level of sugar chosen will also varydepending upon the pressure and level of auxiliary water soluble solidsalso offering a similar increase in osmotic pressure to the aqueousphase of the composition; thus, a variety of low average molecularweight materials may be included as part of the water soluble solids inthe aqueous phase and will augment the sugars in their role of providingsufficient osmotic pressure to prevent bacterial decomposition.

The term "water soluble solids" is used to apply to any additivematerial which is substantially soluble in water at room temperature orat temperatures comparable to those practices in processing theingredients of the foods. Included in the class of water solublenon-sugar solids that can be employed are certain inorganic salts usedat a level compatible with palatability requirements, e.g., sodiumchloride and potassium chloride. Indeed, certain compounds like thediols and polyols, propylene glycol, sorbitol, glycerol and the likewhich have another function, i.e., as an antimycotic and/or texturizer,may also be relied upon to provide the soluble solids (or solutes)employed in the aqueous phase for bacteriostatic protection. Propyleneglycol is prominent in this respect since it is capable of serving amultiple role as mold inhibitor, plasticizing humectant for texture, andcomponent of the water soluble solids of the aqueous phase. The higherdiols, such as the aliphatic 1,3-diols containing four to fifteen carbonatoms in the aliphatic chain and their esters which are completelymetabolized, can also be used, particularly in conjunction with theforegoing sugars and sugar substitutes. These diols also assist inmaintaining the foods in a bacteria-, yeast- and mold-free state whileproviding softness or plasticity to the formulations. These materialsare stable, non-volatile oils with good storage and shelf life andappreciable water solubility, and can be readily emulsified andformulated into various food preparations.

The relative weight percent of said water soluble solids to the moisturecontent of the total product, when initially incorporated into theproduct during its manufacture and preparatory to packaging, determinesthe ulimate functionality of the solids in providing the requisitebacteriostatic effect. The level of water soluble solids may be variedas may the level of moisture initially incorporated within the aforesaidrespective ranges. However, in varying these levels the relationship ofwater soluble solids in solution to the water should be controlled so asto afford the desired osmotic pressure. A good general rule to observein this connection is to be sure that the weight of water soluble solidsavailable for solution is at least equal to the weight of the moisturepresent, although in some cases it is possible that a lower level ofwater soluble solids might afford some protection againstmicrobiological decomposition provided an equivalent degree of osmoticpressure is available. Generally, it will be found that the level ofsugar that should be employed under the conditions of the presentinvention will constitute a major percent by weight of the water solublesolids.

Intermediate-moisture foods have a high sugar content which tends topromote nonenzymatic browning. This phenomenon is caused by complexreactions between the amino groups of proteins and the keto groups ofsugars and is known as the Maillard Reaction. This nonenzymatic browningleads to undesirable darkening of the food product as well as off-odorsand flavors. These reactions can also reduce the nutritional value offoods. Sugars such as dextrose are known to be capable of use at a lowerlevel than sucrose to achieve an equivalent bacteriostatic effect butare reducing saccharides which are prone to undergo the undesirableMillard-type reaction. Fructose is even more susceptible to the browningreaction. This reaction and other oxidative reactions are progressivelyretarded as the temperature is lowered from room temperature torefrigerator temperature to freezer temperature. Hence the products ofthis invention preferably are designed for usage at refrigerator andfreezer temperature unlike the conventional intermediate-moisture foodswhich are stored and used at room temperature, and thus the foods ofthis invention can tolerate the large amounts of dextrose and furctoseused.

the term "sugar" as it is employed in the present context is to beunderstood as meaning any of a number of useful saccharide materialswhich are capable of increasing the osmotic pressure of the water inwhich they are dissolved, thereby giving rise to the requisitebacteriostatic effect. included in the list of useful sugars are themonosaccharides, disaccharides and polysaccharides and their degradationproducts; e.g., pentoses, including aldopentoses, methylpentoses, andketopentoses, like xylose and arabinose; a deoxyaldose like rhamnose;hexoses and reducing saccharides such as aldohexoses like glucose,galactose and mannose; the ketohexoses, like fructose and sorbose;disaccharides, like lactose and maltose; non-reducing disaccharides suchas a sucrose and other polysaccarides such as dextrin and raffinose; andhydrolyzed starches which contain as their constituentsoligosaccharides. Typically, the commercially available mixtures ofinvert sugars are used which contain dextrose and levulose, as well asmaltose and corn syrup solids. The sugars should be of a low molecularweight so as to offer a substantial effect in increasing the osmoticpressure of the sugar solution. The polyhydric alcohols may be used toreplace a portion of the sugars used in this invention and are thereforeencompassed by that term, i.e., from about 0.5 to 5% of the formulationsmay be a polyhydric alcohol such as glycerol and the like.

Since the product of this invention, when prepared in the manner hereindisclosed, is characterized by its substantial resistance of bacterialdecomposition, but may serve as a host for yeasts and mold, the foods ofthis invention may have an antimycotic agent incorporated at a levelsufficient to prevent the growth of such organisms. Sorbate salts suchas potassium sorbate, as well as sorbic acid can be used eitherseparately or in combination. Propylene glycol, which may be used aloneor with other humectants like sorbitol to impart a further degree ofproduct softness or tenderness, can also serve as an antimycotic. Otherantimycotic agents will be apparent to those skilled in the art. Theamount of antimycotic agent added is selected so as to produce thedesired results and will constitute only a minor proportion of theproduct, about 0.1% or higher, depending on the particular antimycoticand the particular product composition, although even lower levels, onthe order of 50 p.p.m., can be employed in the case of such antimycoticsas pimarcin. Potassium sorbate in a water solution can be sprayed ontothe surface of the food or the food can be dipped in this solution;other antimycotics which lend themselves to such surface application areesters of the parabens (parahydroxy benzoate) such as propyl and methylparabens (methyl para-hydroxy benzoate). Cellophane and otherenwrapments for the food can be spray-coated with a sobic acid solution,but impregnation or dusting with sorbic acid or potassium sorbate ispreferred. Antimycotics which can generally be used are benzoic acid,sodium benzoate, propionic acid, sodium and calcium propionate, sorbicacid, potassium and calcium sorbate, propylene glycol, diethylpyrocarbonate, and menadione sodium bisulfite (vitamin K).

Other ingredients known to those skilled in the art may also be employedto impart their characteristic effects to the composition of the presentivention. Typical of such ingredients are flavoring agents, colorants,vitamins, minerals, and the like. Suitable flavoring agents can beemployed to impart vanilla, cream, chocolate, coffee, maple, spice,mint, butter, caramel, fruit and other flavors. Further, fruit which maynot be infused with solutes, may be added to some products of thisinvention. In addition, certain polyols, such as sorbitol and mannitol,can be employed to modify mouthfeel. Furthermore, other additives, suchas phosphates and the like, may be employed for their known functions.Several types of ingredients which can be employed are described below.

Flats high in unsaturation are safflower oil, corn oil, soybean oil,cottonseed oil and sunflower oil. Unsaturated fats as used in thisspecification are those having an iodine value of about at least 50which include partially hydrogenated fats and the more highlyunsaturated fats with an iodine value above about 100. These fats arerecommeded for dietary purposes, particularly for those people with ahigh plasma cholesterol level, a condition associated withatherosclerosis.

The saturated fats include the hydrogenated oil products of coconut,cottonseed, corn, soybean, peanut, olive, etc. Fats having a meltingpoint of 90°-94° F. are preferred, i.e., the melting point should bebelow body temperature.

Emulsifiers are necessary ingredients of those compositions of thepresent invention which contain fats and are oil-in-water emulsions. Awide variety of emulsifiers may be employed in amounts on the same orderas in the prior art oil-in-water emulsions, for example, about from0.1-5%, and preferably about from 0.2-1.5%. They induce the formation ofa stable emulsion and improve the rate of aeration and the totalaeration obtained. Among the more suitable emulsifiers are: hydroxylatedlecithin; mono-, di- or polyglycerides of fatty acids, such asmonostearin and monopalmitin; polyoxyethylene ether of fatty esters ofpolyhydric alcohols, such as the polyoxyethylene ethers of sorbitanmonostearate (polysorbate 60) or the polyoxyethylene ethers of sorbitandistearate; fatty esters of polyhydric alcholos such as sorbitanmonostearate; mono- and diesters of glycols such as propylene glycolmonostearate, propylene glycol monopalmitate, and succinoxylatedmonoglycerides; and the esters of carboxylic acids such as lactic,citric, and tartaic acid with the mono- and diglycerides of fatty acidssuch as glycerol lacto palmitate and glycerol lacto stearate. The fattyacids employed in the preparation of the emulsifiers include thsoederived from beef, tallow, and coconut, cotton seed, palm, peanut,soybean and marine oils. Many blends of emulsifiers are commericallyused and readily available in accordance with techniques. For example,it may be desirable to provide a controlled hydrophil-lipophil balance(HLB) as with a lipophilic emulsifier such as glyceryl monostearate ofsorbitan monostearate with a hydrophilic material such as polysorbate60.

The emulsion compositions of the present invention also include one ormore stabilizers or hydrophilic colloids to imporove the body andtexture of toppings, and as an aid in providing freeze-thaw stability.These stabilizers are natural, i.e., begetable, or synthetic gums andmay be, for example, carrageenin, guar gum, alginate, xanthan gum andthe like, or methylcellulose (Methocle 65 HG), micro-crystallinecellulose and the like, or mixtures thereof. Typically, a gum orcombination of gums is employed with a sugar, e.g., dextrose carrier.The amount of these stabilizers can be varied widely in accordance withthe amounts required in prior art compositions, generally about from0-2%, and preferably about from 0.1-0.5%.

Starches useful in this invention include the new and chemicallymodified starches from potato, arrow root, corn, rice, wheat, waxymaize, sorghym and waxy sorghum. Tapioca starch is particularly suitablefor puddings. Generally about from 0.5 to 2.5% starch is adequate,although in the absence of stabilizers or in some puddings up to about7% may be used.

Protein concentrates and isolates are useful in improving thenutritional qualities of the product and in facilitating and maintaininga whipped structure. Protein also aids in emulsification and contributesto flavor. Bland protein concentrates with a wide range of fibercontent, bland soy flour, milk powder and food proteins are all useful,generally in concentrations about from 0-10%, and preferably about from0.3-3%. Alternatively, use can be made of a protein such as sodium orcalcium caseinate, which is conventional in whipped toppings, or as itssubstitute, a protein hydrolysate in a minor amount.

Many types of salts are used in the compositions of this invention forflavoring, including common salt (sodium chloride), sodium or potassiumphosphates, citrates, chlorides, and the like, in amounts about from0-5%, but preferably about from 0.1-1%.

Antioxidants such as butylated hydroxytoluene, butylated hydroxyanisoleand tertiary butyl hydroquinone may be used in minor amounts (i.e.,Texon 22 antioxidant).

food grade acidulants such as phosphoric, tartaric, malic, citric,fumaric, hydrochloric and the like edible food acids are suitable toimpart tartness, control pH or serve as preservatives.

The following are among the ingredients used in this invention:

The fructose-dextrose syrup used in this invention ("Iso-sweet")comprises 29% water and 71% sugar (50% dextrose, 42% fructose, 1.5%maltose, 1.5% isomaltose and 5% higher saccharides). A highfructose-dextrose syrup contains 23.5% water, with the remainingproportion consisting of 55% fructose and 45% dextrose. A fructoseconcentrate is an aqueous syrup having 80% sugar, of which 90% isfructose and the remainder is dextrose.

Soy protein concentrate is prepared from soybean flakes which areextracted with a solvent system wherein the major protein fraction isimmoblized and the water-soluble carbohydrates, mineral matter, andother minor constituents are removed. The extracted product is dried andground. The concentrate is sold under the name Promsoy-100 by CentralSoya. Whey protein concentrate is sold under the name Empro-50, andcontains 53.6 parts protein and 26.5 parts lactose. A delactosed wheyprotein may also be used.

soybeam oil type 106 is a 100% soybeam oil lightly hydrogenated to aniodine value of 106.

Hard butter type 106 is a blend of 45% palm kernel oil rearranged with5% palm oil and 50% kernel oil hydrogenated to a Wiley Melting point of106° F., and having an maximum iodine value of 1.5.

A standard mixture of mono-and diglycerides is used in manyformaulations. It is sold under the name Drewmulse 20 by PVOInternational, Inc., Boonton, New Jersey, and contains about 43% alphamono content. It has an iodine value of 2.5, a melting point of 140° F.and is manufactured by the glycerolysis of animal or vegetable basedfats.

Tenderex emulsifier is a mixture containing polysorbate 60 (11.9%),sorbitan monostearate (31.6%), mono- and diglycerides or fatty aicds(2.3%), propylene glycol (9.5%) and water (44.3%).

The foregoing conventional ingredients may be used in their normalamounts and may vary from the representative amounts and ranges givenherein. Food formulations and ranges of ingredients do not readilypermit of fixed parameters becuase of variations in people and places.The folllowing examples are not intended to be limiting, but ratherillustative of some approaches taken and of course which may be variedin accordance with the spirit and scope of this description.

Further examples appear in the applicants' copending application Ser.No. 763,613, filed Jan. 28, 1977 now U.S. Pat. No. 4,146,652.

EXAMPLE

A product having wide commerical application is sugared egg yolks. Suchproduct is used in commercial bakeries, and by manufacturers of babyfoods. The sugared yolk product, which is subject to governmentregulation, contains egg yolks, sugar, water and up to about 1% ofadditives such as stabilizers. However, upon freezing, present sugaredyolk products become rock-hard, and must be thawed before such productscan be employed in the preparation of other food products, e.g., thesugar yolk product is too hard for immediate introduction into blendersand mixers. The period needed to permit thawing of present sugared yolkproducts, in addition to being an annoyance, provides an opportunity forcontamination of the sugared yolks and for microbial growth.

In accordance with the present invention a sugared yolk product was madewhich will remain non-crystalline at freezer temperature. This product,accordingly, will be immediately available for use by the food industryin that it can be introduced into mixers and blenders without a thawingperiod. Furthermore, within about 5 to 10 minutes from introduction ofthis product to room temperature, it will be spoonable.

The sugared yolk formulation comprises about 45 to 85% egg yolks, andpreferably about 55 to 70% egg yolks, about 10 to 30% sugar, about 5 to10% water and up to about 1% of a protein stabilizer. The sugar used issubstantially, 75% or more, dextrose plus fructose. The water activityof the sugared yolk product of this invention will be from about0.85-0.90, up to about 0.93.

a sugared yolk formulation was made from the following ingredients inthe indicated amounts.

    ______________________________________                                        Ingredients             Amount                                                ______________________________________                                        (1) Dextrose            8.38                                                  (2) Fructose-Dextrose Syrup                                                                           30.26                                                 (3) Egg Yolk            60.52                                                 (4) Stabilizer          0.84                                                  ______________________________________                                    

Egg Yolks are about 55% water, about 25 to 30% fat, about 15% protein,and miscellaneous minerals, vitamins and other substances. The aboveformulation contains about 40% water and about 32% fructose plusdextrose.

Ingredients (1) through (4) are mixed at low speed for about 2 to 3minutes. After a homogenous blend is obtained, the mixture is whipped athigh speed for about 3 to 5 minutes.

The formulation is non-crystalline at freezer temperatures. After about5 to 10 minutes at room temperature, the formulation is spoonable.

The effect of quinine salt addition to the food products of thisinvention is a reduction in the sweetness of the food product asperceived upon ingestion of the foodstuff. In many cases, the decreasedperception of sweetness associated with the quinine-imbued food productis on the order of 50% of that of the unmodified composition. Additionof quinine substances to food products to lessen the perceived sweetnessof such compounds is postulated to be achieved through masking of theexcessive sweetness occasioned by the sugar through the inherentbitterness of the quinine substance. It is further believed that thisbitterness reduces the duration of perceived sweetness by altering themanner in which the sweetness of the sugar is physiologically perceived.This theory of offered solely by means of explanation, however and isnot intended to limit the scope of the above invention exclusively tothis theory.

This invention has been described in terms of specific embodiments setforth in detail, but it should be understood that these are by way ofillustration only and that the invention is not necessarily limitedthereto. Modifications and variations will be apparent from thisdisclosure and may be resorted to without departing from the spirit ofthis invention, as those skilled in the art will readily understand.Accordingly, such variations and modifications of the disclosed productsare considered to be within the scope of this invention and thefollowing claims.

What is claimed is:
 1. A microbiologically stable sugared egg yolk foodproduct comprising egg yolk, water, sugar, and flavoring, wherein theproduct is substantially non-crystalline at freezer temperatures andcomprises from about 15 to 55% water, sugar in a ratio to water of aboutfrom 0.8-2:1 and a minor but effective amount of flavoring, wherein thesolutes content is adequate to provide the product with a water activityof about 0.8-0.9, the amount of fat is less than the amount of water,and said sugar component comprising at least about 50% dextrose plusfructose based upon the total sugar content, wherein the foregoingingredients are effective to provide an egg yolk product which afterstorage at freezer temperatures is spoonable after a thawing period atroom temperature of about 5 to 10 minutes.
 2. The product of claim 1further comprising up to about 125 p.p.m. of a quinine salt selectedfrom the group consisting of quinine sulfate, quinine bisulfate andquinine hydrochloride.
 3. The product of claim 1 further comprising fromabout 2 at about 75 p.p.m. of a quinine salt selected from the groupconsisting of quinine sulfate, quinine bisulfate and quininehydrochloride.
 4. A microbiologically stable sugared egg yolk productcomprising about 45 to 85% egg yolks, about 10 to 30% sugar, about 5 to10% water and a small, but effective amount, but not more than 1%, ofstabilizer, wherein the amount of dextrose plus fructose is about from75 to 100% based on the total sugar content, provided that the solutescontent is adequate to provide the product with a water activity ofabout from 0.9, and the foregoing ingredients are effective to provide aproduct which is non-crystalline at about 10° F.
 5. The product of claim4 comprising between about 55 to 70% egg yolks.
 6. The product of claim4 wherein the amount of fructose is between about 30 to 40% based uponthe total sugar content.
 7. The product of claim 4 wherein the amount ofdextrose is between about 60 to 70% based upon the total sugar content.8. A method of making a microbiologically stable sugared egg yolk foodproduct which is substantially non-crystalline at freezer temperatureswhich comprises the steps of:(a) forming a mixture comprising egg yolk,water, a sugar component, and flavoring, wherein the mixture comprisesabout from 15 to 55% water, sugar in a ratio to water of about from 0.8to 2:1 and a minor but effective amount of flavoring, wherein thesolutes content is adequate to provide the product with a water activityof about from 0.8 to 0.9, the amount of fat is less than the amount ofwater, and said sugar component is at least about 50% dextrose plusfructose based upon the total sugar content; (b) pasteurizing themixture; and (c) homogenizing the pasteurized mixture; and (d) coolingthe resultant product to between about -5° F. and 10° F., wherein in themixture of step (a) the amount of fructose and dextrose in said sugarcomponent and the ratio of sugar component to water are effective toprovide an egg yolk product which when stored at freezer temperatures isspoonable after a thawing period of about 5 to 10 minutes at roomtemperature.
 9. The method of claim 8 wherein the mixture formedcomprises up to about 125 p.p.m. of a quinine salt selected from thegroup consisting of quinine sulfate, quinine bisulfate and quininehydrochloride.
 10. A microbiologically stable sugared egg yolk foodproduct comprising egg yolk water, a sugar component and flavoring whichis characterized by a water activity of about 0.80 to 0.90, up to about0.93, and by being substantially non-crystalline at freezertemperatures, wherein said sugar component is at least about 50%dextrose plus fructose based upon the total sugar content, and whereinthe amount of fructose plus dextrose, and the ratio of said sugarcomponent to water are effective to provide an egg yolk product whichafter storage at freezer temperatures is spoonable after a thawingperiod of about 5 to 10 minutes at room temperature.
 11. A method formaking a microbiologically stable sugared egg yolk food product which issubstantially non-crystalline at freezer temperatures, which comprisesthe steps of:(a) forming a mixture comprising about 45 to 85% egg yolks,about 10 to 30% sugar, about 5 to 10% water and an effective amount of astabilizer, wherein said sugar component is about 75 to 100% of fructoseplus dextrose based on the total sugar content, the solutes content isadequate to provide the product with a water activity of from about 0.80to 0.90, and (b) homogenizing the mixture, and (c) cooling the resultantproduct to freezer temperatures of from about -5° F. to 10° F., whereinthe amount of fructose plus dextrose and the ratio of said sugarcomponent to water in the mixture of step (a) are effective to provide asugared egg yolk product which after storage at freezer temperatures isspoonable after a thawing period of about 5 to 10 minutes at roomtemperature.
 12. The method according to claims 8 or 11 wherein saidsugar component includes fructose and dextrose.
 13. The method accordingto claim 12 wherein said mixture of step (a) is comprised of about 40%water and about 32% fructose plus dextrose.
 14. The product according toclaims 1, 4 or 10 wherein said sugar is comprised of about 90% fructoseand about 10% dextrose.
 15. The product according to claims 1, 4 or 10wherein said sugar is comprised of about 50% dextrose and about 42%fructose, the remainder of said sugar component being comprised ofmaltose, isomaltose and higher saccharides.
 16. A microbiologicallystable sugared egg yolk food product comprising about 45 to 85% eggyolk, about 5 to 10% water, about 10 to 30% of a sugar component,flavoring, and a stabilizer, which is characterized by a water activityof about 0.8 to 0.90, up to about 0.93, wherein said sugar component isat least about 75 to 100% fructose plus dextrose based upon the totalsugar content, wherein the foregoing ingredients are effective toprovide a sugared egg yolk product which is substantiallynon-crystalline at about 10° F.